Why have objects moved from their original positions when I reopen my Blender file and how do I fix it?
If the objects were keyframed and then moved without setting keyframes once more, the information was not saved with the file and is lost.
You should manually realign the objects this time and in the future if you have animated objects in a similar situation where you don't want the animation, you should select them all, hit F3 and search for Remove Animation function: